v2.26.0: fix SSE fanout crash and branded logo FOUC

- Fix SSE fanout thread AttributeError when source queue is None during
  interpreter shutdown by snapshotting to local variable with null guard
- Fix branded "i" logo rendering oversized on first page load (FOUC) by
  adding inline width/height to SVG elements across 10 templates
- Bump version to 2.26.0 in config.py, pyproject.toml, and CHANGELOG.md

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

utils/adsb_history.py

@@ -6,13 +6,13 @@ import logging
 import queue
 import threading
 import time
+from collections.abc import Iterable
 from datetime import datetime, timezone
-from typing import Iterable
 
 # psycopg2 is optional - only needed for PostgreSQL history persistence
 try:
     import psycopg2
-    from psycopg2.extras import execute_values, Json
+    from psycopg2.extras import Json, execute_values
     PSYCOPG2_AVAILABLE = True
 except ImportError:
     psycopg2 = None  # type: ignore
@@ -20,6 +20,8 @@ except ImportError:
     Json = None  # type: ignore
     PSYCOPG2_AVAILABLE = False
 
+import contextlib
+
 from config import (
     ADSB_DB_HOST,
     ADSB_DB_NAME,
@@ -289,10 +291,8 @@ class AdsbHistoryWriter:
             return True
         except Exception as exc:
             logger.warning("ADS-B history insert failed: %s", exc)
-            try:
+            with contextlib.suppress(Exception):
                 conn.rollback()
-            except Exception:
-                pass
             self._conn = None
             time.sleep(2.0)
             return False
@@ -393,10 +393,8 @@ class AdsbSnapshotWriter:
             return True
         except Exception as exc:
             logger.warning("ADS-B snapshot insert failed: %s", exc)
-            try:
+            with contextlib.suppress(Exception):
                 conn.rollback()
-            except Exception:
-                pass
             self._conn = None
             time.sleep(2.0)
             return False